So the green Kona dew plus is my bike. It's an 8-speed with a 11-34 cassette. It came factory with an Alivio 9-speed derailleur. I need to upgrade the rear derailleur because I got hit by a taxi. My options are slim for 8/9-speed compatible derailleurs. Basically, the Deore RD-M591 and RD-M592. Anything else?

Which would you prefer, the Deore RD-M591 or RD-M592

Second question: What are my options if I wanted to upgrade to 1x and keep my current hub. As I understand it, I can use the Shimano Deore 11s M5100 groupset, 1x11. What about the front chainring? Can I still use my current crank? What front chainring should I get? Do I have other options? How about the Ultegra r8000 derailleur and the road bike flat bar style shifters. Is there a cassette compatible with my hub? Does that even make sense? If I upgrade my hub what better options are there?

  • I don't see how switching to 1× would be an upgrade for this bike. 1× is for full-suspension mountain bikes. For a hybrid bike, the advantages of fine-grained wide-range shifting of a 3× outweigh anything a narrow-wide chainring can offer in terms of chain retention. Commented Aug 21, 2023 at 0:35
  • By now 1x is on various styles of bikes but i know what you mean. The situation is i dont have the front derailleur and shifter anymore. I never used it I.was fine with just the gearing the middle chainring and 8 speed 11 34 cassette provided. Now i have to change the rear derailleur and curious about upgrade options
    – Daniel
    Commented Aug 21, 2023 at 6:12
  • @leftaroundabout Except that the market went for 1x on flat handle bars from mid-range. Shimano has a 2x MTB range, but finding bikes that actually use it is kind of rare (and the 4100 series doesn't offer much more range than a 1x).
    – Rеnаud
    Commented Aug 21, 2023 at 6:43
  • @Renaud "the market went for 1×" – bike manufacturers went for equipping bikes with 1× from the factory. And that makes it a pain to to get a 2× drivetrain on a new bike (though specifically the better Shimano ones really work amazing), but for those people who are blessed with still having a bike that already came with 2× or 3× it's just silly to get rid of it. Granted, a cheap old 3× is not as robust and smooth as more fancy drivetrains, but it's still perfectly usable on reasonably smooth ground and offers nice small gaps. Commented Aug 21, 2023 at 8:50
  • That said, @Daniel if you never even used the other chainrings then apparently you don't have a need for either a new front derailleur or the range of a 1×11 system, so again I don't see why you'd need one rather than just replace the derailleur. Commented Aug 21, 2023 at 8:53

2 Answers 2


The term "direct mount" has been used to mean a few different things with rear derailleurs, and it can cause confusion.

By Shimano's definition, your frame does not have a direct mount. You have the far more common "direct attachment," which most people would just view as a normal, non-weird hanger. Shimano Direct Mount is a different standard for derailleur hanger position relative to the axle. Onto it you install a derailleur such as your Alivio, but you don't use the b-link. In other words, the position of the mounting hole relative to the axle on a Shimano Direct Mount compatible hanger is the same as what the b-link also provides. Notice how in the image, the RDs pictured are the same except for the absence of the b-link on the right.

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If you just wanted to upgrade the RD without altering the drivetrain setup much, yes just get RD-M592. It's a very good part and is basically just an improved version of what you had. M591 would also do the job, as would another of the same Alivio. M591 is not a Shadow derailleur; personally I think Shadow is a good thing because it helps prevent damage, but it's not a critical difference.

If you were going to 1x the bike, your hub is only a limiting factor insofar as it prevents you from running any of the 10t cassettes. So, for example, a mid-price approach would be RD-M5100, an 11-speed shifter for it, an 11-51 11-speed cassette, chain, and switching the middle ring to a narrow-wide with whatever tooth count you decide is right for your gearing needs. The chainline would likely work with the current BB, but you should also be prepared to fiddle with it. Overall it's typically not worth it, although there can be exceptions to that if lots of things are worn out or broken and you intend to keep the bike either way. The road 1x groups don't really offer anything different functionally on a flatbar bike, unless you wanted narrower gearing range. The first question when contemplating a switch to 1x is what your gearing needs are.

  • Thanks so much. Whats still confusing me is in the 3 close up pictures i provided it looks like a direct mount derailleur not using direct hangers. I know for sure the orange bike came from the factory like that with no b link and the same style traditional hanger as mine. Whats up with that?
    – Daniel
    Commented Aug 21, 2023 at 6:04
  • On my green kona I took the front derailleur off so im basically fine with the middle chainring in front and my 11 34 in back. I would just like one faster gear and one better for climbing. I dont want to spend money on a front derailleur and shifter. I may just change to a 9 speed shifter and best range 9 speed cassette i can get away with and just use the middle chainring if the 1x doesn't make sense. I.want to.keep the bike though. It.fits me good so i dont mind spending a few hundred
    – Daniel
    Commented Aug 21, 2023 at 6:04
  • @Daniel None of the derailleurs in those pictures are Direct Mount compatible. They're only for conventional hangers. Only some Shimano RDs are compatible with Direct Mount hangers. Moreover, it's basically a failed effort at this point. They tried pushing it for a few years but it didn't take. Commented Aug 21, 2023 at 6:28
  • Wow it just clicked. Thanks!! What also through me off is websites selling the deore rdm591 like on the orange bike say its direct mouting mec.ca/en/product/6014-185/…
    – Daniel
    Commented Aug 21, 2023 at 6:35
  • @Daniel Yeah, that's what I was talkign about with multiple uses of the term. Before Shimano introduced the Direct Mount hanger that omits the b-link on applicable derailleurs, the term "direct mount" was also in common use to differentiate derailleurs that bolted on to hangers versus between "claw"-type derailleurs that attach to horizontal dropout frames without any integral hanger at all. That's what the link is talking about. Really Shimano should have called it something else. Commented Aug 21, 2023 at 6:39

To complete Nathan's answer, a few points:

  • going to 1x also requires a change of chainring: you need a chainring with a narrow-wide pattern (those are designed to keep the chain, while the current ones are designed to "derail"), and possibly a chainguard. It's usually possible to buy the chainring separately from the crank.
  • road groupsets are usually not designed to be used in 1x configuration and lack the clutch. The ones that can be used are high range ones, and have little added value compared to the mid range MTB ones. Gravel groupsets are also designed to be used in 1x, but again, no added value compared to their MTB equivalents.
  • on top of the M5100, you also have the M5130 Linkglide among the options. It's only 10-speed 11-43, but has a different tooth profile that is in theory more durable. There's also the Advent (9-speed) or Advent X (10-speed) ranges of Microshift.

About the relevancy of upgrading to 1x: if you have to replace the hub and rear derailleur and can keep your current cranks, why not, if you are sure to have all the range with mid-range components (Deore 51x0 or Advent (X)). The extra cost is then limited (shifter and chainring). Compared to the value of the bike, it can be a lot, but the absolute amount remains reasonable. On the technical relevancy, it depends how you use the bike. The only case where I think the 2x/3x have an advantage over 1x is the ability to shift one chainring down when you need to stop suddenly - common in urban riding (in term of effect, you could achieve the same by shifting 3 speeds up rear, that can be done in one stroke, but it is much slower). One advantage I see is not so much in the 1x vs 3x question, but in Deore vs Acera/Alivio: the difference in shifting performance is noticeable - especially on the long run. Just upgrading the rear derailleur (M592) won't give you the same effect, as the shifter matters as well, and you can't find mid-range 9 speed shifters nowadays.

  • Thank you.:) unfortunately im stuck with my standard hg freehub but was thinking about using something like this bikecomponents.ca/collections/groupsets/products/… . Comparing M5100 vs m5130 what would you say? I may keep it simple and get a 9 speed shifter.derailleur cassette and just use my middle chainring. Thats enough gearing for my crusing needs. So it would be silly to use a road derailleur with the trigger style shifters? I was overthinking its super great quality or something
    – Daniel
    Commented Aug 21, 2023 at 6:57
  • If you want to keep the shifter, a 9-speed Shimano-compatible derailleur is the only option (basically anything else than the Microshift Advent), as the actuation is different. The 5130 offers less range and 1 speed less than the 5100, but cassettes and chains are supposed to last longer (but this requires the matching 5130 shifter), depends what you prioritise (range vs durability). The only benefit of changing the hub would be 10T small sprockets, but you don't use/miss now the large chainring, you certainly have no benefit of cassettes with smaller small sprockets.
    – Rеnаud
    Commented Aug 21, 2023 at 7:08

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